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Jacqueline M. Chen Ph.D.
Jacqueline M. Chen Ph.D.

When Laws Change Minds

A new study found that legalizing same-sex marriage accelerated acceptance.

Public sentiment about homosexuality has changed rapidly over the past thirty years. In 1994, only 54 percent of Democrats and 38 percent of Republicans believed that homosexuality should be accepted by society. Fast forward about 20 years, and a majority of people from both parties (83 percent of Democrats and 54 percent of Republicans) believe that society should accept homosexuality1. How did attitudes towards gay people change so much in less than one lifetime? What events precipitated this cultural shift?

Sang Hyun Cho/Pixabay
Source: Sang Hyun Cho/Pixabay

My brand-new research with Eugene Ofosu, Michelle Chambers, and Eric Hehman identified one reason for the rapid change in public sentiment: laws. We obtained two separate datasets2,3 that included over 1 million Americans who responded to questions about their attitudes towards gay people sometime between 2006 to 2016. During the same period of time, states began to legalize same-sex marriage. In 2015, same-sex marriage became legal at the federal level by the Supreme Court’s ruling in Obergefell v. Hodges. By grouping survey respondents together based on their location, it was possible for us to approximate each state’s level of bias against gay people before and after the legalization of same-sex marriage in that state.

Although bias against gay people was already on the decline, it began to drop more quickly after the legalization of same-sex marriage. In other words, legalizing same-sex marriage helped to accelerate public acceptance of gay people. This result held when controlling for various factors, like survey respondents’ age, gender, sexual orientation, and race, and state-level variables like average employment rates and income levels. These findings suggest that legal changes can sway public opinion, improving tolerance for members of stigmatized groups.

There was an alternative explanation for our findings. Critics might argue that the new laws drove people to say that they were more accepting of gay people just because they felt pressure to be politically correct, or “PC.” But we measured people’s attitudes towards gay people with the Implicit Associations Test (IAT), an indirect measure of people’s mental associations outside of their awareness or control. When we examined how the new laws affected people’s associations of “gay people” with “bad,” and we found the same accelerated decline in bias that we observed in people’s responses to survey questions about gay people. Our results suggest that legal changes decreased prejudiced attitudes rather than merely producing a strong norm against expressing prejudiced attitudes.

There was one interesting caveat to our findings. Of the 50 states and DC, there were 15 states who only legalized same-sex marriage as a result of the federal decision. Among these “late adopting” states, we saw some evidence of a backlash effect. Specifically, in those states there appeared to be an increase in prejudice following the Supreme Court decision. We only had data for two years following the federal decision, and so more research is needed to see if the prejudice against gay people continued to increase after 2016 or if prejudiced leveled off or started to decline again. We speculate that the imposition of the federal decision on those 15 states led people to perceive the decision as less legitimate or diagnostic of society compared to people living in states that legalized on their own. For laws to change minds, it is possible that the laws must be perceived as intrinsically motivated by the people.

Institutions guide what people to perceive to be acceptable. One takeaway of our research is that institutional policies and guidelines can be a powerful way to change minds. It is likely that local rules and policies can also affect the opinions and attitudes of your local community. If you are trying to enact social change, consider the ways that policy changes can aid your cause. However, remember that those changes should be perceived as coming from within the institution in order to avoid backlash.


Ofosu, E. K., Chambers, M. K., Chen, J. M., & Hehman, E. (2019). Same-sex marriage legalization associated with reduced implicit and explicit antigay bias. Proceedings of the National Academy of Sciences.


2) Project Implicit Open Data (

3) ANES Data (

About the Author
Jacqueline M. Chen Ph.D.

Jacqueline M. Chen, Ph.D., is an assistant professor of psychology at the University of Utah. Her research examines the psychological processes engaged in diverse social interactions.

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